1. Field of the Invention
The present invention relates to a warp knitted fabric having application with respect to brassieres and, more particularly, to a warp knitted fabric used for brassiere cups which fabric has optimum stability and recovery.
Multi-section sewn brassiere cups in recent years have been replaced by molded brassiere cups. Such molded brassiere cups typically utilize knitted fabrics of continuous filament yarns. In recent years, there has been a gradual evolution with respect to the types of fabrics, and characteristics of same, best suited for such an application. The fabric chosen must, however, have a soft hand after molding, be sufficiently stable, and maintain its shape even after repeated machine launderings.
2. Description of the Prior Art
Brassiere cups have evolved from the sewing together of a number of pieces of fabric, such as cotton, to form a three-dimensional brassiere cup to the molded three-dimensional brassiere cup which is quite common today. Although sewn brassiere cups generally provide satisfactory performance, the ridge or seam lines inherent in such garments oftentimes are aesthetically undesirable to many wearers particularly under sheer garments. As such, there has been a trend in recent years to such molded, "seamless" cups.
Early efforts at producing molded cups involved the use of molded nylon fabrics. The use of such warp knit fabrics made with textured nylon yarns is described, for example, in Textured Yarn Technology Vol. 1, (Monsanto, 1967) at pages 374-381. See also, Merrill G. R., Cotton Ring Spinning, Mass. (Merrill, 1959) at pages 88,90; and Reisfeld, A., Warp Knit Engineering, (New York National Knitted Outerwear Association, 1966) at 50-61, 76-83, 462-3.
Because of the polymeric structure of nylon which does not lend itself to shape retention, subsequent developmental efforts concentrated, instead, on polyester yarns. Problems however, were encountered in molding uniform brassiere cups with woven polyester constructions and, as such, the developmental efforts switched to knitted rather than woven polyester constructions. Initially, multifilament polyester yarns were used followed by monofilament polyester yarns. Although monofilament yarns provided a more stable fabric, they are coarse or have a rough hand. Accordingly, efforts have been made to correct such problems by the stitch construction of the fabrics.
U.S. Pat. No. 3,981,310, which issued on Sept. 21, 1976 to James G. Donaghy, and is owned by the assignee of the present application, describes a particularly advantageous warp knit fabric construction which uses continuous and monofilament polyester yarns. The Donaghy patent provides three bar, warp knit fabric which includes a top or front, middle, and a bottom or back guide bar yarns. The front bar includes multifilament yarns including polyester. The middle and back bars include monofilament polyester yarns. The front bar may be in a 2/3-1/0 or a 3/4-1/0 stitch configuration. The middle and back bars preferably are in a 1/0-1/2 and a 1/2-1/0 stitch configuration, respectively. Such constructions constituted a substantial improvement over the prior art attempts in that the resultant molded fabric was capable of being molded and retained its shape and support after a number of launderings.
The Donaghy patent relies on a three bar, warp knit machine which is relatively expensive to run. The ability to achieve a hand similar to the warp knit fabric of Donaghy with a two bar machine would provide a distinct commercial cost advantage in the marketplace. Attempts at producing such a fabric on a two bar machine have, to date, still failed to achieve the hand, stability and recovery characteristics heretofore possible only with a warp knit fabric produced on a three bar machine.
The use of one or two bar warp knit machines is not new, although, fabrics knit with such machines have generally lacked the requisite hand, stability and recovery characteristics required for use in a molded brassiere cup. See, for example, U.S. Pat. No. 4,015,451, which issued on Apr. 5, 1977 to B. J. Gajjar, and which describes a number of different loop patterns which may be formed on a two bar machine.
An alternative version of a two way stretch warp knit fabric formed on a two bar machine is discussed in U.S. Pat. No. 4,064,712 which issued on Dec. 27, 1977 to J. F. Sayre et al. The front bar in Sayre et al. includes a two needle overlap progression for each loop. A 2/0-2/4 front bar pattern and an alternative 2/4-3/1-4/2-0/2 front bar patterns are both discussed.
Other examples of two bar warp knit machines include U.S. Pat. Nos. 3,027,738 which issued on Apr. 3, 1962 to W. Turton and 1,666,638 which issued on Apr. 17, 1928 to E. J. Bennett; and German Pat. No. 649,553 which issued on Aug. 30, 1937. See also, U.S. Pat. No. 4,502,302, which issued on Mar. 5, 1985 to Y. Matsuda.
Examples of warp knitting on a single bar machine include, for example, French Pat. No. 2419-990, which issued on Nov. 16, 1979, and which shows in examples 4, 5 and 7 (FIGS. 7-12) a stitch pattern of 2/0-1/3 which is formed on a single bar machine. See, also U.S. Pat. No. 4,307,587, which issued on Dec. 29, 1981 to H. Baesgen, et al., and which discusses a single bar warp knit pattern wherein the loop extends at least over three stitches. Three stick versions of the 2/0-1/3 pattern are shown in FIGS. 4 and 5.
However, the fabrics produced on such one and two bar machines lack the hand, stability and recovery characteristics required for forming a molded brassiere cup.